Tell me, is it good idea for Apex ax-14: "R20 should be reduced to at least 50 Ohms, otherwise you will get the work of pre-exit in class AB. And shunt it the film 1mkF." ?
Drivers bias with 220R is about 5mA, with 50R bias will be about 20mA before outputs start conducting.
The P30 preamplifier can be powered on +/-15v?
Yes, but better use +/-24V or +/-18V.
So, that was a bad idea?Drivers bias with 220R is about 5mA, with 50R bias will be about 20mA before outputs start conducting.
fh11
hiii every one
i made fh11 with 3 pair irf640/irf9640
for bias use 2/2k multiturn
but 2n551's be hot ..what i do?
For $2.50 each (all inclusive) I got 10 of these boards.
It will last a while until I can test it. The heat sinks are still on order.
P.S. Of course PCBs arrived! (No possibility to correct the headline!)
hiii every one
i made fh11 with 3 pair irf640/irf9640
for bias use 2/2k multiturn
but 2n551's be hot ..what i do?
hi i made this instead of 1kmulititurn insert 2k
and mje 350 be hot plz insert heat sink
and 2n5551 so be hot....what i do?
hi i made this instead of 1kmulititurn insert 2k
and mje 350 be hot plz insert heat sink
and 2n5551 so be hot....what i do?
Replace 150R resistor with 330R.
Inductor Help
I am putting together all the parts to build the FH11 (Mouser order came in today) so I'm trying to get everything laid out.
I am working on the inductor - which the silkscreen says should be 2.0uH, but other threads are from 1.0 - 2.0uH (how low is still ok?)
Questions - (using 16Ga 1.2mm enameled wire) I made two different diameter versions, both with 10-11 turns of wire:
- one around a pencil, approx 7mm internal diameter
- one around a AA battery, approx 11mm internal diameter
Pencil version measures 0.6uH (on left in pics)
AA battery version measures 1.6uH (on right in pics)
Which one should I use? I like the look of the pencil version since it fits the designated area on the board with out crowding surrounding components, but don't want to comprimise the quality just because of that.
I am putting together all the parts to build the FH11 (Mouser order came in today) so I'm trying to get everything laid out.
I am working on the inductor - which the silkscreen says should be 2.0uH, but other threads are from 1.0 - 2.0uH (how low is still ok?)
Questions - (using 16Ga 1.2mm enameled wire) I made two different diameter versions, both with 10-11 turns of wire:
- one around a pencil, approx 7mm internal diameter
- one around a AA battery, approx 11mm internal diameter
Pencil version measures 0.6uH (on left in pics)
AA battery version measures 1.6uH (on right in pics)
Which one should I use? I like the look of the pencil version since it fits the designated area on the board with out crowding surrounding components, but don't want to comprimise the quality just because of that.
Attachments
2SA1943,2SC5200 transistors manufactured by ON Semiconductor, are of good quality?
or you know where to order good quality?
thank you!
or you know where to order good quality?
thank you!
Sir,Yes, but better use +/-24V or +/-18V.
Can you suggest a power supply other than Apex class A for powering P30? Coz parts for Class A PSU are difficult to source here...
Hi.. Which pre amp did you use?I made this PSU to power a preamp.
Separate dual rectifier for + and -
Very good sound improvement.
Can you please show the schematics of the psu?
OPT changes?
Miles, thank you for your knowlege, experience and contributions.
What changes would be necessary to use 2SB1560 & 2SD2390 for the OPT's?
Possible to use in the AX14, AX15, AX16, AX17, AX18, AX20 and BX20?
I have 11 extra pairs of these SB/SD devices. Each device will have 0R47 degen emitter resistors.
I have a choice of 2 transformers:
48-0-48 rails @ 350VA
56-0-56 rails @ 300VA.
I await your reply.
Kind regards,
Karl Beistline
Miles, thank you for your knowlege, experience and contributions.
What changes would be necessary to use 2SB1560 & 2SD2390 for the OPT's?
Possible to use in the AX14, AX15, AX16, AX17, AX18, AX20 and BX20?
I have 11 extra pairs of these SB/SD devices. Each device will have 0R47 degen emitter resistors.
I have a choice of 2 transformers:
48-0-48 rails @ 350VA
56-0-56 rails @ 300VA.
I await your reply.
Kind regards,
Karl Beistline
Sir,
Can you suggest a power supply other than Apex class A for powering P30? Coz parts for Class A PSU are difficult to source here...
How about the Apex shunt regulator?
100W Ultimate Fidelity Amplifier post #2029.
I have PDF for the layout.
How about the Apex shunt regulator?
100W Ultimate Fidelity Amplifier post #2029.
I have PDF for the layout.
Thanks for the suggestion.
HAve you built it?
Kindly post the layout files/pdf.
Thanks and regards,
Sumesh
do some reading on the forum,
class -A or shunt regs are better (in my reading) than chip regs. In this thread, read Jwilhelm's post for class-A.
Read Salas shunt reg thread for Mr. N. Pass's B1 buffer!
regs
Prasi
Can you please help me to locate this thread? I am looking for a good pre amp PSU.
Regards,
Sumesh
- Home
- Amplifiers
- Solid State
- 100W Ultimate Fidelity Amplifier